System for treating supraventricular tachyarrhythmias

• US 20030199928A1
• Filed: 05/22/2003
• Published: 10/23/2003
• Est. Priority Date: 03/19/1998
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: KenKnight, Bruce H., Hsu, William
• Granted Patent: US 6,873,873 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

A system and method for treating atrial fibrillation using atrial pacing pulses to convert an atrial fibrillation to non-fibrillation atrial arrhythmia prior to delivering a low energy cardioversion/defibrillation shock. The system and method treats atrial fibrillations by first applying a plurality of pacing pulses to the atria which converts the atrial fibrillation to non-fibrillation atrial arrhythmia. Ventricular intervals are concurrently sensed and analyzed while the plurality of electrical pacing pulses are being applied. Upon detecting a period of stable ventricular intervals, the system then proceeds to deliver a low-energy cardioverting/defibrillating pulse of electrical energy across the atria of the heart.

Claims

1. A system for treating a heart, comprising:

an implantable housing;

a first atrial catheter attached to the implantable housing of the system, where the first atrial catheter has a first atrial electrode and a first defibrillation electrode, and is positioned within the heart with the first atrial electrode and the first defibrillation electrode in a supraventricular region of the heart;

a ventricular catheter attached to the implantable housing of the system, where the ventricular catheter has a first ventricular electrode, and is positioned within the heart with the first ventricular electrode in a right ventricular chamber of the heart; and

electronic control circuitry within the implantable housing, connected to the first atrial electrode, the first defibrillation electrode, and the first ventricular electrode and where the electronic control circuitry receives cardiac signals through the first atrial electrode and the first ventricular electrode, and upon detecting atrial fibrillation, delivers a plurality of pacing pulses to convert the atrial fibrillation to a non-fibrillation atrial arrhythmia, analyzes the ventricular intervals for stability and delivers a first level atrial shock to the heart during a period of stable ventricular intervals.

2. The system of claim 1, wherein the system further includes a second atrial catheter attached to the implantable housing of the system, where the second atrial catheter has a second atrial electrode and a second defibrillation electrode, and is positioned within the heart with the second atrial electrode and the second defibrillation electrode in the supraventricular region of the heart;

and wherein the electronic control circuitry is connected to the second atrial electrode and the second defibrillation electrode and receives cardiac signals through the first and second atrial electrodes and the first ventricular electrode, and upon detecting atrial fibrillation, delivers the plurality of pacing pulses to convert the atrial fibrillation to the non-fibrillation atrial arrhythmia.

3. The system of claim 2, wherein if the ventricular intervals are not stable during the plurality of pacing pulses, the electronic control circuitry repeats delivery of the plurality of pacing pulses.

4. The system of claim 3, wherein the electronic control circuitry repeats delivery of the plurality of pacing pulses two or more times, including a final repeat attempt, during which if a period of stable ventricular intervals is not detected the electronic control circuitry delivers an atrial defibrillation shock to the heart after the final repeat attempt.

5. The system of claim 4, wherein the first atrial catheter is an endocardial lead releasably attached to the implantable housing.

6. The system of claim 5, wherein the second atrial catheter is an endocardial lead releasably attached to the implantable housing.

7. The system of claim 6, wherein the ventricular catheter includes a second ventricular electrode, and is positioned within the heart with the first and second ventricular electrodes in the right ventricular chamber of the heart.

8. The system of claim 1, wherein the first level atrial shock is a low-energy shock having an energy level capable of restoring a sinus rhythm during the non-fibrillation atrial arrhythmia.

9. The system of claim 1, wherein the control circuitry receives a first atrial signal through the first atrial electrode, determines an atrial rate from the first atrial signal, compares the atrial rate to a predetermined threshold rate, and detects the atrial fibrillation when the atrial rate is greater than the predetermined threshold rate.

10. The system of claim 1, wherein the control circuitry receives a first ventricular signal through the first ventricular electrode, monitors ventricular contractions in the first ventricular signal during the delivery of the plurality of pacing pulses, determines ventricular intervals each being a time interval between two successive ventricular contractions, monitor a stability of the ventricular intervals, and indicates that the atrial fibrillation has been converted to non-fibrillation atrial arrhythmia if the ventricular intervals are stable.

11. The system of claim 10, wherein the control circuitry calculates a standard deviation of the ventricular intervals, compares the standard deviation to a predetermined stability threshold, and indicates that the ventricular intervals are stable if the standard deviation is smaller than the predetermined stability threshold.

12. The system of claim 1, wherein the implantable housing includes an exposed electrically conductive portion to allow delivery of at least one of the plurality of pacing pulses and the first level atrial shock between the first atrial electrode and the exposed electrically conductive portion of the implantable housing.

13. The system of claim 12, wherein the first atrial catheter includes a second atrial electrode and a second defibrillation electrode, and is positioned within the heart with the first and second atrial electrodes and the first and second defibrillation electrodes in the supraventricular region of the heart, and wherein the electronic control circuitry is connected to the first and second atrial electrodes and the first and second defibrillation electrodes and receives cardiac signals through the first and second atrial electrodes and the first ventricular electrode, and upon detecting atrial fibrillation, delivers the plurality of pacing pulses to convert the atrial fibrillation to the non-fibrillation atrial arrhythmia.

14. The system of claim 13, wherein the first atrial electrode, the second atrial electrode, and the exposed electrically conductive portion of the implantable housing allow delivery of the plurality of pacing pulses between any combination thereof, and wherein the first defibrillation electrode, the second defibrillation electrode, and the exposed electrically conductive portion of the implantable housing allow delivery of the first level atrial shock between any combination thereof.

15. A system for treating a heart, comprising:

means for detecting an atrial fibrillation of the heart;

means for delivering a plurality of pacing pulses to the heart;

means for determining whether the atrial fibrillation has been converted to a non-fibrillation atrial arrhythmia; and

means for delivering a low-energy shock to the heart if the atrial fibrillation has been converted to the non-fibrillation atrial arrhythmia, the energy of the low-energy shock capable of restoring the heart to a sinus rhythm during the non-fibrillation atrial arrhythmia.

16. The system of claim 15, wherein the means for determining whether the atrial fibrillation has been converted to non-fibrillation atrial arrhythmia comprises:

means for sensing ventricular contractions;

means for determining ventricular intervals based on the ventricular contractions; and

means for monitoring a stability of the ventricular intervals.

17. The system of claim 15, wherein the means for delivering the plurality of pacing pulses to the heart comprises means for delivering the plurality of pacing pulses to at least one of a first and second atrial pacing locations.

18. The system of claim 17, wherein the means for delivering the low-energy shock to the heart comprises means for delivering the low-energy shock to at least one of a first and second atrial defibrillation locations.

19. The system of claim 18, further comprising means for delivering an atrial defibrillation shock to the heart.

20. The system of claim 19, wherein the means for delivering the atrial defibrillation shock to the heart comprises means for delivering the atrial defibrillation shock to at least one of the first and second atrial defibrillation locations.